As long as you don't remove mypage.php. If the include() function can't find a page it will generate an error. So if you want to disable gzip you would need to comment out the gzip code on mypage.php like this:
<?php
/*
if (substr_count($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) ob_start("ob_gzhandler");
else
ob_start();
*/
?>